Various handheld or portable lighting devices, including flashlights, are known in the art. Flashlights typically include one or more dry cell batteries having positive and negative electrodes. In certain flashlights, the batteries are arranged in series in a battery compartment of a barrel or housing that can be used to hold the flashlights. An electrical circuit is frequently established from a battery electrode through conductive means which are electrically coupled with an electrode of a light source, such as a lamp bulb or a light emitting diode (“LED”). After passing through the light source, the electric circuit continues through a second electrode of the light source in electrical contact with conductive means, which in turn are in electrical contact with the other electrode of a battery. Typically, the circuit includes a switch to open or close the circuit. Actuation of the switch to close the electrical circuit enables current to pass through the lamp bulb, LED, or other light source—and through the filament, in the case of an incandescent lamp bulb—thereby generating light.
Conventional flashlights also frequently include a head assembly, which typically includes a head, a lens, a face cap, and a reflector. The face cap in such flashlights is typically attached to the head to hold the lens and reflector relative to the head. Head assemblies of this type are often threadably mounted to the forward end of the body or barrel of the flashlight via the head. Such head assemblies are not conducive, however, to accessing a light source alignment device, such as the light source alignment devices included in the flashlights described in U.S. Pat. No. 7,264,372 B2 (“the '372 patent”) or U.S. Patent Publication 2007/0064354 A1 (“the '354 publication”), both of which are assigned to MAG Instrument, Inc.
The '372 patent teaches a head assembly including a face cap, lens, a sleeve or skirt, and a sealing O-ring that are configured and arranged so that the face cap and sleeve define a clearance envelope surrounding the flange of a reflector module to solve this problem. As a result, the head assembly may be rotated about the axis of the flashlight relative to reflector module so as to cause the light source to translate along the axis of the reflector and vary the dispersion of light produced by the flashlight. Further, the user may disengage the sleeve or skirt from the face cap and then slide it rearward to gain access to the light source alignment device and thereby move the light source in one or more directions lateral to the axis of the reflector to align the substantial point source of light with the axis of the reflector. The disadvantage of this construction is that when the sleeve or skirt is disengaged from the face cap, the face cap, and hence the lens, are no longer connected to the reflector module or any other portion of the flashlight, and hence they are liable to be dropped and/or damaged.
The flashlight described in the '354 publication solves this problem through the use of a support structure to which the face cap and skirt (which is referred to as the head in the '354 publication) are separately attached. The face cap is threadably attached to the support structure of the flashlight and retains the lens and reflector relative to the support structure. Thus, when the skirt is detached from the support structure to gain access to the light source alignment device included in the flashlight of the '354 publication, the face cap and associated optics remain attached to the flashlight, thereby minimizing the potential for damage to the same. However, the skirt of the '354 patent publication is attached to the support structure via a compressible retaining ring. More particularly, the internal surface of the skirt is configured to mate with the outer surface of the support structure of the flashlight at select locations to properly position the skirt relative to the face cap and the support structure. The compressible retaining ring is then provided in a channel extending around the outer surface of the support structure to create an interference fit with a feature provided on the internal surface of the skirt. Because the skirt must be removable in order for the user to access the light source alignment device included in the flashlight described in the '354 publication, however, the compressible retaining ring may not provide a permanent type interference fit. Indeed, to permit the average user to remove the skirt without undue effort, the interference fit must be relatively weak. As a result, the skirt of this flashlight is subject to being unintentionally disconnected from the support structure if the flashlight is dropped on its tail or otherwise receives a jolt to the tail of the flashlight. The unintentional detachment of the skirt from the support structure in this manner is undesirable.
Although the '372 patent and '354 publication indicate that the light source employed in the flashlights described in each of the patent documents may be an LED, these patent documents do not teach a configuration that suitably addresses the thermal management issues created by high power, high brightness LEDs.
Some advanced portable lighting devices provide multiple functions for different needs. For example, a power saving mode and/or an SOS mode may be implemented in a flashlight or other portable lighting devices in addition to the normal “full power” mode. In such portable lighting devices, the user typically elects the desired mode of operation by manipulation of the main power switch. For example, when the flashlight is in the normal mode or the power save mode of operation, the flashlight may be transitioned to another mode of operation, such as an SOS mode by manipulating the main power switch to momentarily turn off and then turn back on the flashlight.
Typically the functionality of multi-mode portable lighting devices of this sort is provided by a microcontroller, which remains powered by the batteries at all times. As a result, the volatile memory of the microcontroller may be used to remember the current mode of the flashlight, and thus determine which mode to transition into in the event that a user enters the proper command signal. However, if the portable lighting device—particularly in the case of larger flashlights—is accidentally hit against or dropped on a hard surface, the inertia of the battery or batteries may cause the battery or batteries to disconnect from one of the battery contacts for a short period of time. This disconnection will also cause a power loss to the microcontroller, thereby causing the microcontroller to lose track of the mode the flashlight or other lighting device was in prior to the power loss. As a result, the microcontroller will reset the flashlight or other lighting device to its default mode, which is typically off, rather than automatically returning to the prior mode of operation. Resetting under such circumstances is undesirable and potentially hazardous.
Portable lighting devices that include advanced functionality typically include a printed circuit board with a microcontroller or microprocessor to provide the desired functionality. A need exists, however, for a push button switch assembly that includes an integral circuit board that may be readily employed in a variety of portable lighting devices to provide multiple levels of functionality to the same.
In view of the foregoing, a need exists for an improved technique of attaching a flashlight skirt to the flashlight while also providing a user friendly operation when detaching the skirt. A separate need also exists for an improved portable lighting device that addresses or at least ameliorates one or more of the problems discussed above.